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Discussion Starter · #1 ·
New to composite and suspension. Got this for nothing, wondering if it can be rebonded, screwed, glued, etc. Thanks for input.


 

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It's a Trek Y-bike I'm guessing? Pretty much toast really. You could glue it on, but then only use it for wall art. I wouldn't think any fix would be strong enough for you to safely ride the bike.
 

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Looks like it was welded in place from what i can see in your pics,why not take it to a alloy welding shop,get it welded back on by some one that knows what they are doing then test with a 40ft drop off :)
 

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Discussion Starter · #4 ·
Frame is composite btw, mount is aluminum. Tough to draw an arc on carbon.

Looks like it was welded in place from what i can see in your pics,why not take it to a alloy welding shop,get it welded back on by some one that knows what they are doing then test with a 40ft drop off :)
 

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Rogue Exterminator
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I have this flow chart that will help you determine if it is repairable.

can-it-be-fixed.jpg
 

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Just sand the part and frame and glue it back on. I would make a slurry out of some cut down fibers and epoxy in a 50/50 mix by weight. Just get a really good glue! ask a few pros whats good. It was glued there by the factory and so can you.
 

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Yes it can be fixed. the process to repair it and make it last is a bit detailed to do correctly, but not difficult with the proper supplies.

The composite frame should be taped to protect the finish and then sand lightly to remove the old adhesive and lightly expose the fibres.

The aluminum lug needs to be lightly abraded in the bonding are the prepped with a product called AC 130. This will chemically clean the surface and provided a form of adhesion prep better than bare aluminum.

You will need to find some very fine fiberglass cloth such as style 120 to insulate the aluminum from the carbon or if you can find a coarser scrim cloth even better.

Epoxy wise, you need a product that is acceptable to bond composites to aluminum. The product can not be enhanced with aluminum powder such as JB weld or any of the gray colored epoxy products. A good choice with coarse scrim could be Hysol 9309.3NA. If you use the style 120 glass as a scrim, you need to work the 9309.3NA into the cloth to ensure there is no dry area and minimal bubbles.

When you plan to bond this, the rear shock and swingarm need to be used to align the bracket. Once aligned, apply pressure without the bracket moving, squeeze out the excess epoxy ensuring a bead is formed all the way around the bracket. Once aligned, and content with the pressure, carefully apply heat while maintaining pressure and alignment.Use a heat gun and slowly warm the part,first to around 100f for say 30 minutes, then increase the heat about 5f per minute to around 150f. This will ensure the strongest bond.

On the flip side, you may try to clean and prep the are, wipe it down with acetone then try the JB weld. It may hold for a while, or maybe not, but can always be rebonded if it fails. Just be certain to constantly inspect it and as mentioned before it will be for old school type xc riding, drops or big hit stuff will kill the frame quickly.
All the best with it.

PK
 
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